1. Field of the Invention
This invention relates to an automotive air conditioner for conditioning air in a room of an automobile. The automotive air conditioner of the present invention is effectively applied to an automobile which does not have a surplus heat source such as, for example, an electric automobile.
2. Description of the Prior Art
Usually, an automotive air conditioner makes use, in order to heat air, of heat from cooling water for an engine for driving an automobile. However, heating of air is performed using a heat pump when the amount of heat of cooling water for an engine is insufficient or when an automobile does not originally have engine cooling water such as an electric automobile.
For example, in an automotive air conditioner disclosed in Japanese Patent Laid-Open Application No. 60-219114, a flow of refrigerant is changed over by means of a four-way valve such that an inside heat exchanger is used either as an evaporator to cool air or as a condenser to heat air.
With the automotive air conditioner wherein cooling operation and heating operation are performed alternatively by changing over of a four-way valve in this manner, since the single heat exchanger changes its function immediately between a function of an evaporator and another function of a condenser, there is the possibility that, particularly when the function is changed over, a large amount of moisture may be blasted from a surface of the inside heat exchanger toward the inside of the room of the automobile.
In particular, water condensed on a surface of the inside heat exchanger during cooling operation is evaporated from the surface of the inside heat exchanger as a result of changing over to heating operation and then carried into the room of the automobile by a blower. Such blasting of a large amount of water will instantaneously fog a windshield and/or window glass. The fog will make an obstacle to a field of view in driving the automobile and is very inconvenient.